Projected shifts in the distribution of Anopheles funestus under future climate scenarios in Malawi

Understanding how climate change may reshape the ecological distribution of Anopheles funestus is critical for informing adaptive malaria control in Malawi. This study applied MaxEnt species distribution modelling, integrating occurrence records with bioclimatic variables derived from CMIP6 projections (HadGEM3-GC31-LL), to estimate habitat suitability for a 1950–2020 baseline and for 2021–2040, under SSP2-4.5 and SSP5-8.5 scenarios. The model performed strongly (AUC = 0.90), with mean temperature of the driest quarter (Bio9, 48.6%) and precipitation of the warmest quarter (Bio18, 27.4%) as key predictors. Under SSP2-4.5, the mean Habitat Suitability Index (HSI) increases by 109% (from 0.571 to 1.194), reflecting intensification of suitability within core habitat zones. However, spatial analysis reveals a 35.6% contraction in the total extent of marginally suitable habitat. Approximately 45,113 km2 of previously marginally suitable areas become unsuitable, while gains are concentrated in suitable (+ 8,029 km2) and highly suitable (+ 6,594 km2) zones, indicating a redistribution and ecological clustering. Under SSP5-8.5, the mean HSI increases by 40.6% (to 0.804), with more pronounced spatial polarization. High suitability zones (HSI > 1.5) cover 20–45% of Northern and eastern regions. The Central Region exhibits a peak mean HSI of 1.80, suggesting strong ecological intensification. These findings point to a future of increasingly fragmented yet climatically optimal habitats for Anopheles funestus, potentially elevating localized transmission risks. Climate-responsive strategies must incorporate habitat forecasting, expand vector surveillance in emerging hotspots, and adapt interventions to shifting ecological conditions. The results underscore the urgency of integrating climate projections into malaria preparedness and vector control in Malawi and beyond.